Overview
- The FLORA study enrolls patients with advanced liver cancer. Experts also refer to this type of cancer as hepatocellular carcinoma.
- Patients are eligible to participate if the cancer cannot be treated surgically, and a liver transplant or other local treatments are not valid treatment options. An additional requirement is that treatment with the standard first-line anticancer drugs atezolizumab and bevacizumab is planned.
- In the study, researchers are testing whether healthy gut bacteria can help the immune system during cancer treatment and improve the effectiveness of the cancer drugs. To this end, gut bacteria from healthy donors are transferred to patients. This treatment is known as a “fecal microbiota transplantation.”
Study status: The study is enrolling patients (recruitment open).
Hepatocellular carcinoma is the fifth most common cancer worldwide. Research efforts are extensive, as hepatocellular carcinoma has a high mortality rate and ranks fourth globally among cancer-related causes of death.
There are now several treatment options for hepatocellular carcinoma. The available options depend on the stage of the disease and the patient’s overall health.
One option for advanced-stage disease is treatment with the anticancer drugs atezolizumab and bevacizumab.
- Atezolizumab is an immune-checkpoint-inhibitor and is a form of immunotherapy against cancer.
- Bevacizumab is a drug from the group of the so-called targeted cancer drugs that prevents the tumor from forming new blood vessels and continuing to grow.
However, this combination therapy produces the desired effect in only a small number of patients. There are numerous potential reasons for this lack of efficacy. Through research, scientists are attempting to uncover these reasons and to find ways to improve the effectiveness of this therapy.
One possible approach is to positively alter the balance of natural gut bacteria and thereby support the immune system. Researchers aim to achieve this through fecal microbiota transplantation (FMT).
In the FLORA study, researchers are investigating whether FMT can improve the efficacy of drug therapy with atezolizumab and bevacizumab, and whether it is safe for patients with hepatocellular carcinoma.
- For more details on the specific goals the scientists are pursuing with FLORA, see the section “What is the goal of the FLORA study?”.
The full title of the FLORA study is, “Fecal Microbiota Transfer in Liver Cancer to Overcome Resistance to Atezolizumab/Bevacizumab – A randomized, placebo-controlled, double-blind Phase II trial.”
In other words:
- The study investigates the transfer of healthy gut bacteria in patients with hepatocellular carcinoma being treated with atezolizumab and bevacizumab.
- The goal is to overcome therapeutic resistance—characterized by a diminishing or loss of efficacy from a specific therapy—in this case concerning the combination of atezolizumab and bevacizumab.
Objectives of the FLORA Study
The aim of the study is to examine how the drugs atezolizumab and bevacizumab, in combination with FMT and the antibiotic vancomycin, affect the immune system.
In FLORA researchers will:
- Assess safety: Determine if the combination of atezolizumab/bevacizumab, vancomycin (an antibiotic), and FMT is a safe treatment regimen.
- Evaluate immunogenicity: Test whether the combination enhances the immune response against the tumor by measuring immunogenicity levels (i.e., the triggered immune response).
- Assess efficacy: By determining, for example, how long patients survive after treatment and in how many participants tumor growth was inhibited.
In addition, the researchers hope to learn more about this form of hepatocellular carcinoma and the associated health issues through the study.
Who is the study suitable for?
Patients can participate in the FLORA study if all of the following criteria are met:
- The participant is at least 18 years old.
- The patient has hepatocellular carcinoma that cannot be cured by surgery, liver transplantation, or local treatment.
- Patients may be treated with atezolizumab and bevacizumab in accordance with standard treatment recommendations.
- The study physicians consider the patients' liver function to be adequate despite existing damage like liver cirrhosis.
- Patients are able to manage their daily lives largely on their own.
- Current computed tomography, CT images of the chest and magnetic resonance imaging, MRI or CT scans of the abdomen are available. The results must not be older than 30 days prior to the start of treatment. The scans can also be performed as part of the preliminary examinations at the study center.
- A blood test has been performed to check for infection with hepatitis B or C. In the case of an active hepatitis B infection, only a small amount of virus should be detectable in the blood, and ongoing treatment should be continued. In the case of an active hepatitis C infection, it is important that hepatitis treatment be continued during participation in the study.
- Certain blood count and laboratory values (such as kidney and liver function tests) must be sufficiently normal.
- Sexually active individuals must commit to using highly effective contraceptive methods during the study and for 6 months afterward. Physicians will provide information on suitable contraceptive methods.
- Women who can become pregnant must provide proof via a pregnancy test that they are not pregnant.
- Women who are breastfeeding cannot participate in the study.
- The participant has understood what will happen in the study, the potential consequences of participation, and is able to adhere to the study protocol and dosing schedule.
- The participant has signed a consent form.
- The patient consents to biopsy of the tumor. For this, the tumor must be easily accessible for tissue sampling.
Patients who meet any of the following criteria cannot participate in the FLORA study:
- One of the above points does not apply.
- The participant has taken medications that suppress the immune system within the last 6 months prior to the start of the study.
- The patient has an autoimmune disease or a chronic inflammatory condition.
- The person has previously received immunotherapy for cancer.
- The patient is HIV-positive or has concurrent hepatitis B and hepatitis C infections.
- During a gastroscopy within the last 12 months, varicose veins were found in the stomach or esophagus that could bleed.
- The participant has severe, untreatable nausea and vomiting, a chronic gastrointestinal disorder, difficulty swallowing, or has a history of major intestinal surgery. These factors could prevent the study drug from being properly absorbed or processed.
- The patient has high blood pressure despite medication.
- The patient has, or has had, a serious kidney disease.
- The patient has taken antibiotics 2 weeks prior to being assigned to the study groups.
- The participant has taken probiotics within the week prior to the start of therapy (with atezolizumab and bevacizumab). These are preparations that contain lactic acid bacteria.
- The participant has a specific or rare form of hepatocellular carcinoma (e.g., fibrolamellar, sarcomatoid, or diffuse-growing type) or a mixed form of hepatocellular carcinoma and cholangiocarcinoma.
- The participant has had another type of cancer in the past 5 years.
- The patient has received a live vaccine within the last 30 days prior to the start of therapy.
- There is a known hypersensitivity or allergy to any of the medications (vancomycin, atezolizumab, bevacizumab, the FTM investigational drug INTESTIFIX-001). This also applies to allergies to structurally similar medications or any of the excipients contained therein.
- The patient is participating in another clinical trial involving drug treatment or an ongoing follow-up phase.
- The patient is institutionalized due to an official or court order or is legally unable to give consent on their own behalf.
The FLORA study is a:
- Double-blind study: Neither the participants nor the researchers know who is receiving the investigational drug for fecal microbiota transfer (INTESTIFIX-001) and who is receiving the placebo. This prevents the placebo effect from skewing the results.
- Randomized study: In a randomized study, it is decided at random who receives the investigational drug and who receives the placebo. This allows the results to be evaluated as objectively as possible.
- Multicenter study: Patients can participate at various study centers in Germany.
- Phase II study: Researchers are testing how safe and effective FMT is in patients with hepatocellular carcinoma (in addition to therapy with atezolizumab or bevacizumab).
(1) Consultation and preliminary examinations
The FLORA study team first determines whether interested patients are eligible to participate in the study. To do this, the doctors conduct several examinations and review existing medical records. In addition to information about the patient’s medical history, they also need details about any medications currently being taken. If there are no obstacles to participation, the participant must sign the informed consent form.
Before treatment begins, patients undergo a comprehensive examination:
- Doctors perform a comprehensive physical examination, measuring key vital signs such as heart rate, blood pressure, and body temperature. They also record height and weight.
- The doctors perform a rectal examination. During this procedure, tissue samples (biopsy) are taken.
- The study team draws blood from the participants. In addition, patients must provide a urine sample and a stool sample.
- The doctors check whether the participants’ hearts are functioning properly. To do this, they perform an electrocardiogram (recording of the heart rhythm).
- For women who can become pregnant, the study team performs a pregnancy test.
- The study team performs imaging procedures such as a computed tomography, CT scan and a magnetic resonance imaging, MRI scan.
- Doctors will perform a gastroscopy if one has not been done in the past 6 months.
- The study team assesses health-related quality of life using a questionnaire. Participants must complete this questionnaire several times over the course of the study.
(2) Randomisation
Before treatment begins, participants are randomly assigned to either the placebo or the FMT treatment group (randomisation). Twice as many patients are allocated to the FMT group as to the placebo group. Neither the participants nor the doctors on the study team know who is receiving the test drug and who is receiving the placebo. Experts refer to this as double-blind.
(3) Pre-treatment
First, all patients receive a 3-day pre-treatment: the FTM group is given the antibiotic vancomycin, while the placebo group receives corresponding placebo capsules. All participants keep a diary to record when and how they took the medication.
(4) Treatment phase
After the pre-treatment, the actual therapy begins:
On the first day of treatment, participants receive an infusion of the medications atezolizumab and bevacizumab. At the same time, they take a single dose of 15 FTM capsules (or placebo capsules).
Treatment with atezolizumab and bevacizumab consists of a total of 4 phases (cycles), each lasting 3 weeks. At the start of the 2nd cycle, participants again take 15 FTM or placebo capsules.
In the two subsequent cycles (cycles 3 and 4), the participants will receive only the infusions without taking any more capsules.
The treatment lasts about 12 weeks in total.
(5) Examinations during treatment
During treatment with atezolizumab, bevacizumab, and FMT (or placebo), the study doctors will regularly check the participants’ health status.
The following examinations will take place during the study:
- Physical examinations and vital signs monitoring (e.g., blood pressure and pulse)
- Blood and stool sample collections
- Rectal examination with biopsy
- Health-related quality of life questionnaires
- Progress monitoring via imaging procedures (e.g., computed tomography, CT or magnetic resonance imaging, MRI)
- Participant surveys on side effects, health status, and well-being
(6) Follow-up
All patients will be followed up for a period of 12–36 months starting from the time of treatment with FMT or the placebo. This includes follow-up visits every 3 months with the study physicians, as well as follow-up examinations with the treating physicians outside of the study.
(7) Further Treatment
After the study ends, the treating physician will discuss the next steps with the participants. Together, they will decide whether and how treatment with standard therapies will continue and which follow-up appointments are appropriate.
These are the potential benefits of participating in the FLORA study:
- There is a possibility that fecal microbiota transplantation (FMT) could make cancer treatment with atezolizumab and bevacizumab more effective and boost the body’s immune response against hepatocellular carcinoma.
- Furthermore, the study’s results may help improve the treatment of hepatocellular carcinoma in the future.
However, participating in the FLORA study may also have disadvantages:
- The effectiveness of fecal microbiota transplantation (FMT) in combination with the drugs atezolizumab and bevacizumab has not yet been proven. It is therefore possible that participants will not experience the expected benefits.
- It is also possible that participants will be assigned to the treatment group receiving the placebo: if FTM proves beneficial, they will not benefit from it.
- Treatment with the antibiotic and the FTM investigational drug (INTESTIFIX-001) may lead to side effects such as diarrhea, abdominal pain, nausea, or digestive problems. These can vary in severity but are often treatable.
- The examinations conducted as part of the study may involve certain risks or burdens, such as blood draws or biopsies. The study physicians will provide detailed information about these and other risks.
Where is the study being conducted?
The FLORA study is taking place at various NCT sites in Germany. Study centers that are already recruiting are: Augsburg, Regensburg, Ulm, Tübingen, Heidelberg, Cologne, Essen, and Berlin.
The option to participate at the Mannheim study center is currently being prepared.
What costs will participants incur?
Participation in the study is free of charge for patients. However, you will not receive any compensation for your time or expenses. Travel costs are not reimbursed as part of the study.
If you have questions about the study’s funding, you can ask the study team, for example during the informational meeting.
How can I sign up?
Referring physicians or patients who wish to participate in the study can contact us via email at the following address:
Studienzentrale-leber.med4-at-med.uni-heidelberg.de
The study team will then contact you.
Scientific Publications (Selection)
Rauber C, Roberti MP, Vehreschild MJ, Tsakmaklis A, Springfeld C, Teufel A, Ettrich T, Jochheim L, Kandulski A, Missios P, Mohr R, Reichart A, Waldschmidt DT, Sauer LD, Sander A, Schirmacher P, Jäger D, Michl P, Dill MT. Protocol: Fecal microbiota transfer in liver cancer to overcome resistance to atezolizumab/bevacizumab—a multicenter, randomized, placebo-controlled, double-blind phase II trial (the FLORA trial). BMJ Open. 2025 Sep 9;15(9): e097802. doi: 10.1136/bmjopen-2024-097802. PMID: 40930564; PMCID: PMC12421604.
R. S. Finn, S. Qin, M. Ikeda, P. R. Galle, M. Ducreux, T.-Y. Kim, M. Kudo, V. Breder, P. Merle, A. O. Kaseb, D. Li, W. Verret, D.-Z. Xu, S. Hernandez, J. Liu, C. Huang, S. Mulla, Y. Wang, H. Y. Lim, A. X. Zhu, A.-L. Cheng, Atezolizumab plus Bevacizumab in Unresectable Hepatocellular Carcinoma. N. Engl. J. Med. 382, 1894–1905 (2020).
B. Routy, E. Le Chatelier, L. Derosa, C. P. M. Duong, M. T. Alou, R. Daillère, A. Fluckiger, M. Messaoudene, C. Rauber, M. P. Roberti, et al., Gut microbiome influences efficacy of PD-1–based immunotherapy against epithelial tumors. Science 359, 91–97 (2018). doi: 10.1126/science.aan3706.
This study description was prepared by authors from the Cancer Information Service, under the direction of Dr. S. Weg-Remers, based on the study documentation.